LES study on turbulent dust deposition and its dependence on atmospheric boundary-layer stability

Abstract. It is increasingly recognized that atmospheric boundary-layer stability (ABLS) plays an important role in aeolian processes. While the effects of ABLS on dust emission have been documented in several studies, those on dust deposition are less well studied. By means of large-eddy simulation, we investigate how ABLS influences the probability distribution of surface shear stress and hence dust deposition. Statistical analysis of the model results reveals that the shear stress can be well approximated by using a Weibull distribution and the ABLS influences on dust deposition can be estimated by considering the shear stress fluctuations. The model-simulated dust depositions are compared with the predictions of a dust-deposition scheme and measurements, and the findings are then used to improve the dust-deposition scheme. This research represents a further step towards developing dust schemes that account for the stochastic nature of dust processes.